Investigation the Effect of Partial Root Drying Deficit Irrigation under Different Irrigation Regimes and Plant Density on Grain Yield and Water Productivity of Grain Millet in Arid Region of Kashmar

This research was conducted as a split plot experiment based on completely randomized design with three replications at natural resources and agricultural research center of Kashmar. Irrigation treatments including full irrigation (i.e. providing 100% irrigation water requirement of plant), 80, 60 and 40% irrigation water requirement were as main plots and plant density treatments including density of 10, 20 and 30 plants per square meter were as sub-main plots. The results showed that irrigation treatments and plant density were significant on some traits such as plant height, 1000-grain weight, grain yield and water productivity (WP) at one level percentage (p < 0.01). Interaction of irrigation treatments and density was only significant on biologic yield and panicle no. per plant. The highest grain yield and WP with quantities of 3395 Kg/ha and 0.87 Kg/m3 respectively, was observed for full irrigation treatment and density of 10 plants per square meter. In all of the irrigation treatments by increasing the plant density, the biologic yield decreased significantly. There was no significant difference among the harvest index in all of the deficit irrigation treatments. Considering the effect of drought stress and increasing of plant density was significant in grain yield and WP reduction, it is recommended that full irrigation method and density of 10 plants per square meter was applied for planting of grain millet in Kashmar region.